Lifting-jack.



No. 787,435. PATBNTED APR. 1a, 1905. E. 000K.

LIFTING JACK.

APPLICATION FILED JUNE 6.1904.

, pivoted on the frame A.

UNITED STATES Patented. April 18, 1905.

PATENT OFFICE.

LlF'l'lNG-JACK.

SPECIFICATION forming part of Letters I atent No. 787,435, dated April18, 1905.

Application filed June 6, 1904. Serial No. 211,344.

To all whom, it may concern:

Be it known that I, EUGENE CooK, a citizen of the United States,residing at the city of Kalamazoo, county of Kalamazoo, State ofMichigan, have invented certain new and useful Improvements inLifting-Jacks, of which the following is a specification.

This invention relates to improvements in lifting-jacks.

The main object of this invention is-to provide an improved lifting-jackwhich may be tripped with comparative ease even while sustaining a heavyload.

Further objects and objects relating to structural details willdefinitely appear from the detailed description to follow.

I accomplish the objects of my invention by the devices and meansdescribed in the following specification.

The invention is clearly defined, and pointed out in the claims.

A structure embodying the features of my invention is clearlyillustrated in the accompanying drawings, forming a part of thisspecification, in which Figure 1 is a side elevation view, partially insection, to show the arrangement of parts of a structure embodying thefeatures of my invention. Fig. 2 is a detail sectional view taken online 2 2 of Fig. 1 looking in the direction of the little arrows at theends of the section-lines, showing the relation of the triphook F to theholding-pawl. Fig. 3 is an enlarged side elevation view of the trip-hookF in an inverted position.

In the drawings similar letters of reference refer to similar partsthroughout the several views.

Referring to the drawings, A is the frame, and B is the lifting-bar, thelifting-bar being provided with suitable ratchet-teeth on one side. Theshank Got the operating-lever is A lifting-pawl E is pivotally securedon the inner end of the shank (J. A holding-pawl D is supported abovethe lifting-pawl by a suitable pivot on the frame A. This holding-pawlis adapted to retain the lifting-bar during the downward movements ofthe lifting-pawl.

In operation the lifting-bar B is elevated by means of the lever.

The pawl E engages the bar, so that when the lever'is forced downwardlythe bar is elevated. The retainingpawl D engages the bar and holds itinits elevated position until released or until the lever is againoperated to further elevate the bar, when theoperation is repeated.

i A trip-hook F is pivotally secured at c to the shank C of theoperating-lever for disengaging the pawls to release the lifting-bar.This trip-hook is adapted to engage a laterally-projecting pin e towardthe upper end of the lifting-pawl E and is also provided with alaterally-projecting lug or pin f, adapted to engage the inner face ofthe holding-pawl D to disengage it. This lug or pin is so arranged thatthe pawl D is disengaged from the lifting-bar before the trip-hook actsupon the pawl Ethat is, the pawls are acted upon successively. I

The holding-pawl D is notched at d for the passage of the pin f, so thatwhen the triphook is thrown inwardly and the operatinglever elevated itwill automatically drop into place, the pin f dropping behind the pawlD.

With the trip-hook in its engaging position, as illustrated in Fig. 1,the operating-lever is forced downwardly, which, as stated, firstwithdraws the holding-pawl D from the lifting-bar and then thelifting-pawl E. As the line of pull is comparatively direct on the endof the lifting-pawl, it is much more easily withdrawn than theholding-pawl when sustaining a full load. By this arrangement of parts Iam enabled to withdraw the holdingpawl while the main portion of theload is sustained by the lifting-pawl. The liftingpawl is then withdrawnby a comparatively direct pull on the pawl, as stated, so that I amenabled to trip the jack while under a heavy load with comparative ease.While the load is being lifted, the trip is thrown outwardly against therest 0 on the shank, as is indicated by dotted lines in Fig. l.

The parts of my improved lifting-jack are very simple to construct anddurable in use. I have illustrated and described my invention in theform preferred by me on account of the simplicity and economy ofstructure, although I am aware that the same may be varied in 100structural details without departing from my invention.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. In a lifting-jack, the combination of a frame; a lifting-bar; anoperating-lever; a lifting-pawl pivotally secured to the inner end ofsaid operating-lever and having a laterallyprojecting pin toward itsupper end; a holding-pawl having a not-ch in one edge thereof pivotallysupported on said frame; atrip-hook pivotally secured to said leveradapted to engage the laterally-projecting pin on the lifting-pawl andhaving a laterally-projecting pin thereon adapted to pass through thesaid notch in said holding-pawl and engage the inner face thereof, saidpin being so arranged as to withdraw said holding-pawl from engagementwith said lifting-bar before said lifting-pawl is acted upon, for thepurpose specified.

2. In a lifting-jack, the combination of a frame; a lifting-bar; anoperating-lever; a lifting-pawl pivotally secured to the inner end ofsaid operating-lever; a holding-pawl pivoted on said frame; a tripmember pivotally secured to said lever adapted to engage said pawlssuccessively, whereby said holding-pawl is withdrawn from engagementwith said lifting-bar before said lifting-pawl is acted upon, for thepurpose specified.

3. In a lifting-jack, the combination of a lifting-bar; anoperating-lever; a lifting-pawl pivotally secured to the inner end ofsaid operating-lever; a holding-pawl coacting with the saidlifting-pawl; a trip member pivotally secured to said lever, adapted toengage said pawls successively whereby they are Withdrawn successivelyfrom engagement with the said lifting-bar, for the purpose specified.

In witness whereof I have hereunto set my hand and seal in the presenceof two witnesses.

EUGENE COOK. [L. s]

Witnesses:

ETHEL A. TELLER, OTIS A. EARL.

